[PPR Nav] Fix flash of loading state during back/forward

[acdlite]

Depends on

• Shard PPR navigations tests into multiple files #60577

---

A popstate navigation reads data from the local cache. It does not issue new network requests (unless the cache entries have been evicted). So, when navigating with back/forward, we should not switch back to the PPR loading state. We should render the full, cached dynamic data immediately.

To implement this, on a popstate navigation, we update the cache to drop the prefetch data for any segment whose dynamic data was already received. We clone the entire cache node tree and set the prefetchRsc field to null to prevent it from being rendered. (We can't mutate the node in place because Cache Node is a concurrent data structure.)

Technically, what we're actually checking is whether the dynamic network response was received. But since it's a streaming response, this does not mean that all the dynamic data has fully streamed in. It just means that some of the dynamic data was received. But as a heuristic, we assume that the rest dynamic data will stream in quickly, so it's still better to skip the prefetch state.

Closes NEXT-2084

[ijjk]

Tests Passed

[ijjk]

Stats from current PR

Default Build (Increase detected ⚠️)

General Overall increase ⚠️

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
buildDuration	13.2s	13.2s	N/A
buildDurationCached	7.4s	6.5s	N/A
nodeModulesSize	200 MB	200 MB	⚠️ +19 kB
nextStartRea..uration (ms)	410ms	416ms	N/A

Client Bundles (main, webpack) Overall increase ⚠️

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
193.HASH.js gzip	181 B	182 B	N/A
3f784ff6-HASH.js gzip	53.3 kB	53.3 kB	N/A
433-HASH.js gzip	28.8 kB	28.9 kB	⚠️ +139 B
framework-HASH.js gzip	45.2 kB	45.2 kB	✓
main-app-HASH.js gzip	239 B	242 B	N/A
main-HASH.js gzip	31.8 kB	31.8 kB	N/A
webpack-HASH.js gzip	1.7 kB	1.7 kB	N/A
Overall change	74 kB	74.1 kB	⚠️ +139 B

Legacy Client Bundles (polyfills)

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
polyfills-HASH.js gzip	31 kB	31 kB	✓
Overall change	31 kB	31 kB	✓

Client Pages

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
_app-HASH.js gzip	194 B	195 B	N/A
_error-HASH.js gzip	183 B	181 B	N/A
amp-HASH.js gzip	504 B	502 B	N/A
css-HASH.js gzip	321 B	321 B	✓
dynamic-HASH.js gzip	2.5 kB	2.5 kB	N/A
edge-ssr-HASH.js gzip	255 B	253 B	N/A
head-HASH.js gzip	350 B	349 B	N/A
hooks-HASH.js gzip	369 B	369 B	✓
image-HASH.js gzip	4.28 kB	4.28 kB	N/A
index-HASH.js gzip	255 B	256 B	N/A
link-HASH.js gzip	2.61 kB	2.61 kB	✓
routerDirect..HASH.js gzip	312 B	311 B	N/A
script-HASH.js gzip	385 B	383 B	N/A
withRouter-HASH.js gzip	307 B	308 B	N/A
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Overall change	3.4 kB	3.4 kB	✓

Client Build Manifests

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
_buildManifest.js gzip	483 B	484 B	N/A
Overall change	0 B	0 B	✓

Rendered Page Sizes

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
index.html gzip	529 B	527 B	N/A
link.html gzip	541 B	540 B	N/A
withRouter.html gzip	524 B	522 B	N/A
Overall change	0 B	0 B	✓

Edge SSR bundle Size

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
edge-ssr.js gzip	93.8 kB	93.8 kB	N/A
page.js gzip	148 kB	148 kB	N/A
Overall change	0 B	0 B	✓

Middleware size

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
middleware-b..fest.js gzip	622 B	624 B	N/A
middleware-r..fest.js gzip	151 B	151 B	✓
middleware.js gzip	37.5 kB	37.5 kB	N/A
edge-runtime..pack.js gzip	1.92 kB	1.92 kB	✓
Overall change	2.07 kB	2.07 kB	✓

Next Runtimes

	vercel/next.js canary	acdlite/next.js ppr-nav-fix-flash-of-loading	Change
app-page-exp...dev.js gzip	169 kB	169 kB	✓
app-page-exp..prod.js gzip	95.2 kB	95.2 kB	✓
app-page-tur..prod.js gzip	95.9 kB	95.9 kB	✓
app-page-tur..prod.js gzip	90.5 kB	90.5 kB	✓
app-page.run...dev.js gzip	142 kB	142 kB	✓
app-page.run..prod.js gzip	89.8 kB	89.8 kB	✓
app-route-ex...dev.js gzip	24.1 kB	24.1 kB	✓
app-route-ex..prod.js gzip	16.7 kB	16.7 kB	✓
app-route-tu..prod.js gzip	16.7 kB	16.7 kB	✓
app-route-tu..prod.js gzip	16.3 kB	16.3 kB	✓
app-route.ru...dev.js gzip	23.5 kB	23.5 kB	✓
app-route.ru..prod.js gzip	16.3 kB	16.3 kB	✓
pages-api-tu..prod.js gzip	9.38 kB	9.38 kB	✓
pages-api.ru...dev.js gzip	9.65 kB	9.65 kB	✓
pages-api.ru..prod.js gzip	9.37 kB	9.37 kB	✓
pages-turbo...prod.js gzip	21.9 kB	21.9 kB	✓
pages.runtim...dev.js gzip	22.5 kB	22.5 kB	✓
pages.runtim..prod.js gzip	21.9 kB	21.9 kB	✓
server.runti..prod.js gzip	49.6 kB	49.6 kB	✓
Overall change	940 kB	940 kB	✓

Diff details

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Diff for 433-HASH.js

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Commit: 40f4493